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Increasing the efficiency of gas production from marine gas hydrate still faces significant problems. Based on the geological survey of marine reservoirs, gas hydrates are generally associated with underlying free gas layers with high temperature and water saturation. Here the effect of this gas layer and its characteristics on the gas and water production from the hydrate layer are studied. It was found that a large temperature difference existed between the two layers during gas production due to the different heat demand and consumption in each layer. Slower gas production rate was observed in case of dense distribution of hydrates in the hydrate-bearing layer and the resulting sluggish gas permeation and enormous heat supply. Notably, this was not present when the free gas layer was more water-saturated. The resulting maximum gas production rate could be effectively enhanced by 41 % at most as well. This was attributed to the increased sensible heat available from the pore water and the interbedded heat exchange. It was thus indicated that a hydrate reservoir with an underlying water-rich layer could be more favorable for gas production in terms of heat supply. • Joint exploitation through pre-embedding compartment device and vertical well. • A significant temperature difference between the two layers during exploitation. • Highly water-saturated underlying shallow gas layer enhance hydrate decomposition. [ABSTRACT FROM AUTHOR]

An empirical land allocation model is developed and fit to production data of the top five crops in the USA and to crop output prices adjusted for direct payments and subsidies. The land allocation model based on the theory of the multiproduct firm allows for jointness in production, and it is extended to handle non-allocable inputs. Specifically, the model is used to analyze whether the Food Security Act of 1985, known as the 1985 Farm Bill, increased flexibility in land allocation decisions by comparing responsiveness of land allocation among the crops, before and after the passage of the 1885 Farm Bill, to changes in total land availability and changes in crop output prices. The results confirm that a structural change in land allocation dynamics took place after the passage of the 1985 Farm Bill. We show that more crops (wheat and soybeans, in particular) become more acreage responsive to the changes in total land available for production after 1985. For example, the results indicate that competition for acreage between corn and wheat is associated with the implementation of the 1985 Farm Bill. The results provide evidence that the onset of the increased acreage allocation flexibility by farmers originated in the policies of the 1985 Farm Bill. The study also demonstrates that a policy targeting a particular crop will inadvertently affect production of other crops. This study quantifies these indirect effects on the five major crops grown in the USA. [ABSTRACT FROM AUTHOR]

This study investigated the possibility to perform statistical optimization of an enriched mixed microbial consortium, MMC, fed in continuous with a highly inhibiting 2G glycerol, for the joint production of 1,3 propanediol (1,3 PDO) and butyric acid (BuA). Key variables taken into consideration were HRT, pH and feed concentration. The optimized process reached a glycerol consumption rate of 137 g/L/d and a maximum predicted production rate of 82.61 g/L/d and 21.13 g/L/d for 1,3 PDO and BuA, respectively. This corresponded to a 2.2 and 1.9-fold increase compared to the non-optimized process. The model was able to satisfactorily predict the joint maximum production of 1,3 PDO and BuA (22.6 and 8.1 g/L respectively) of the steady state also in non-sterile conditions, implying thus that MMC can be a robust and reliable biological production platform. [ABSTRACT FROM AUTHOR]

The paper discusses the economic analysis of modern rich economies. It argues that standard economic theory acknowledges that it does not apply if there is own‐consumption and/or joint production and suggests that successful economic reforms of the 1980s have used markets to drive down costs in sectors where standard economic theory applies. This process has resulted in a situation where rich country economies are increasingly oriented to sectors – predominantly services – where markets work less well, namely those with extensive own‐consumption and joint production, where theory says that factor rewards and other prices cannot be determined by production and consumption conditions. Arguing that this can explain the “wages squeeze,” the paper concludes that other economic mechanisms should and have arisen to secure better welfare gains, thus explaining the recent shift in policy priorities of the ACTU. [ABSTRACT FROM AUTHOR]

Summary: The divide between attributional and consequential research perspectives partly overlaps with the long‐standing methodological discussions in the life cycle assessment (LCA) and input‐output analysis (IO) research communities on the choice of techniques and models for dealing with situations of coproduction. The recent harmonization of LCA allocations and IO constructs revealed a more diverse set of coproduction models than had previously been understood. This increased flexibility and transparency in inventory modeling warrants a re‐evaluation of the treatment of coproduction in analyses with attributional and consequential perspectives. In the present article, the main types of coproductions situations and of coproduction models are reviewed, along with key desirable characteristics of attributional and consequential studies. A concordance analysis leads to clear recommendations, which call for important refinements to current guidelines for both LCA/IO practitioners and database developers. We notably challenge the simple association between, on the one hand, attributional LCA and partition allocation, and on the one hand, consequential LCA and substitution modeling. [ABSTRACT FROM AUTHOR]

Purpose: Developing a robust method for CO2 allocation in oil refineries is an ongoing debate within the life cycle assessment (LCA) community. Several methodologies reported in the literature, mostly performing sequential and iterative calculations, tend to be biased toward diesel at the expense of gasoline, failing to properly consider the role played by hydrogen. This paper develops a new non-iterative refinery CO2 allocation method to explore the concept of customized allocation to overcome the inherent bias in standard methods.Methods: The allocation methodology is based on a system of linear equations built around the material and energy balances of a refinery. After describing the process of building such system, it is shown that the carbon allocation values of all final products and intermediate streams are directly obtained by solving it. A numerical example of CO2 emission allocation to major refinery products is provided from an optimized refinery linear programming (LP) case for the European refining industry, based on literature projections for 2020.Results and discussion: The paper presents the key emission sources in the European refinery sector, and by using a standard mass-based allocation technique, we show that the carbon intensities of refined petroleum products derived using the non-iterative method are consistent with other studies. We confirm the findings that the standard allocation typically used in attributional refinery LCA tends to reward diesel to the detriment of gasoline. We attempted reconciling this by applying a reallocation factor to customize the CO2 allocation to represent the “real” economic purposes of process units reflecting the constraints European refineries face today. This moderated the octane production effects given the important role the reformer plays in hydrogen co-production, where the emission burden of highly knock-resistant reformate is redistributed to hydrogen and carried through to diesel.Conclusions: By customizing the allocation of CO2, we demonstrated that the differences between a consequential and an attributional approach in refinery LCA can partly be reconciled. We now run into the risk of increasing the subjectivity of the attributional method by using “judgment calls” to decide on the choice of weightage to be applied. We invite the wider LCA practitioners to further investigate the use of this new non-iterative method for allocating CO2 and explore the concept of reallocation factors as means to customize emission allocation. [ABSTRACT FROM AUTHOR]

In recent times, the issue of a “Phosphate Peak” has entered the academic debate and it is widely present in social media. Arguments in favour and against are similar to those mentioned in the much earlier debate on the “Oil Peak”. However, whereas the “Oil Peak” is supply driven, the “Phosphate Peak”, if at all, is demand driven. In contrast with oil, most of which is chemically transformed in CO2, vapor and other constituting elements, phosphate is not “consumed” during its primary use as a fertilizer. Hence, whilst phosphate rock, from which phosphate is mined, is a depletable resource, phosphate itself is potentially recyclable and re-usable. Research on the technologies for such a recovery is manifold and, specifically, efforts are spent on waste water as a source of phosphate. This, if successful, could lead to a changing perception of waste water treatment plants as a set of backstop technologies to eliminate an environmental problem into a “secondary liquid mine” from which phosphate, but not only phosphate, could be extracted for re-use. Hence, for that purpose, an economic model of efficient extraction of phosphate and other elements from waste water in a waste water treatment plant could give guidance to operators. This paper presents such a model describing the optimal simultaneous extraction of several elements, including phosphate, from a “secondary liquid mine”. The elements are assumed to be present in given proportions (ratios) in this “mine” and the model shows that these ratios have an impact on the optimal extraction path and on resulting “implicit” shadow pricing rules to be adopted by the waste water treatment plant operator. [ABSTRACT FROM AUTHOR]

Context Economists define non-market ecosystem services (ES) as public or common goods due to their characteristics of non-rivalry in terms of consumption and/or non-excludability. Just because they do not have a price does not mean that ES have no economic value because their social benefits are undoubtedly considerable. These features, associated with the market demand for timber and a poor climate risk assessment, may lead to the under-provision of non-market forest ES and the over-harvesting of timber. Aims In this article, we review research questions that are central to the enhancement of FES provision. Beyond the economic modelling of the joint provision of FES, we focus on issues related to the design of public policies to guide forest management. The objective is to provide crucial insights concerning the importance of a spatial and sustainable provision of FES. Results First, we provide an economic interpretation of the FES concept and a review of economic models of forest management. Second, we explain how spatial and temporal dimensions of FES can have major implications on their supply and demand. Both dimensions explain why FESs have to be taken into account in production decisions and public policies (including the design of payment for environmental services (PESs)). Conclusion A better understanding of FES provision and public policies to be enhanced is not possible without accounting for spatial and temporal dimensions. This helps to analyse the impact of intervention on FES and the cost-effectiveness of economic instruments, implying a coordinated effort to bring together ecological and economic data and models. [ABSTRACT FROM AUTHOR]

Low gas production efficiency and high cost significantly impede the commercial viability of exploiting marine gas hydrate. To address this, we propose joint production of hydrate and shallow gas, focusing on previously unexplored characteristics such as fluid seepage and local deformation arising from interlayer interface. In this study, we investigate the coupled multiphysics response during depressurization in joint production. Our findings reveal that the joint production enables gas production rates to surpass commercialization threshold, with the minimum proportion of free gas in total production exceeding 0.5 during depressurization stage. Free gas stored in the reservoir promotes the energy recovery, which is correlated with permeability. We observe the water block effect, a type of interlayer interference, leading to local gas accumulation in three phase layer and heterogeneous gas effective permeability change within reservoir. Regarding geomechanical behavior, the maximum displacement occurs in the free gas layer during the 100-day test. Simultaneous compaction occurs in the upper part of the wellbore, whereas dilation is observed in the lower part. This study offers crucial insights into the characteristics and challenges of hydrate and shallow gas joint production related to interlayer interference. • Joint production enables gas production rates to surpass commercialization threshold. • Minimum ratio of free gas in total production exceeds 0.5 during depressurization stage. • Local gas accumulation is observed in reservoir due to water block effect. • Local deformation (settlement and uplift synchronous) exists around the wellbores. [ABSTRACT FROM AUTHOR]

The paper discusses the diffusion of new technologies from the perspective of the classical economists and Schumpeter. After a comparison of the pre- and post-technical change long-period positions of the economy, we illustrate the process of transition between the two in terms of a two-sector model. Next, we turn to a system with joint production. The fact that some products may be "bads" that need to be disposed of leads to a study of systems of production-cum-disposal. Finally, we investigate the selection pressure innovations exert on incumbent firms. An important message is that technical change cannot generally be studied within a partial framework of the analysis. [ABSTRACT FROM AUTHOR]

This paper explains the "positive profits with negative surplus-value" example of Steedman (1975) and shows that while in joint production systems individual labour values can be negative, the claim that the total labour embodied in the surplus product of the economy (surplus-value) can also be negative is based on assumptions that have no economic meaning (such as negative activity levels).The paper also provides a way to measure the surplus-value of joint production systems which overcomes the problems of the traditional concept and restates the proposition that a positive amount of surplus labour is a necessary condition for positive profits. [ABSTRACT FROM AUTHOR]

The nonperforming loans (NPLs) are co-generated by creating the profit in a bank, and this article build a joint production model to measure the reduction cost of nonperforming cost. By using a data set of China's 13 commercial banks, the conclusions show that the reduction cost of NPLs is lower, which suggests that it is not a good choice for China's commercial bank to hold the NPLs. [ABSTRACT FROM AUTHOR]

The Chicago Mercantile Exchange introduced a futures contract for distillers' dried grains (DDGs) in early 2010, but the market became inactive only four months after its inception. While many new futures contracts do not develop into high-volume traders, interest from DDG cash market participants indicated that this contract could be successful. Prompted by the unexpected lack of trading activity in this new futures market, we empirically revisit the question of what factors contribute to a futures contract's success and extend the literature by investigating the roles of market participants and the significance of supporting futures markets. Estimation results indicate that the market participant type-hedger or speculator-affects futures contract trade volume. More importantly, we find that the viability of new futures contracts for commodities that are jointly produced with other commodities is impacted by hedgers' trade volume of the related futures contract. These results provide important additions into the portfolio of indicators used by commodity exchanges to more cost-effectively evaluate new futures contract products. [ABSTRACT FROM AUTHOR]

Labor values, reproduction prices and land rent. The paper analyses the determination of labor values and reproduction prices, including economic systems with joint production and systems with intensive land rent. The discussion is based on very simple numeric examples, avoiding that the mathematical complications hinder the comprehension of basic questions of Marxist economic theory.