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Vinasse, a byproduct of ethanol production from sugarcane, is a rich organic matter and poses environmental challenges due to its high pollutant content. Effective biomethane production from vinasse can mitigate its environmental impact by converting organic matter into a useful energy source while reducing its pollutant load. The biomethane production by anaerobic digestion (AD) process of the vinasse byproduct was examined on a laboratory scale. In this regard, several loads from 0.5 to 7 g VS/L were investigated to assess AD performance and methane production. This study investigated how two separate factors, namely the load and hydraulic retention time (HRT), affect both cumulative methane production (CMP) and methane yield (YCH4). This investigation utilized a response surface methodology known as the central composite design (RSM-CCD). Statistical analysis of variance (ANOVA) was employed to evaluate the effectiveness of the model generated. Thus, the model's fit, YCH4 has a maximum R2 value of 0.9759. The results revealed an astounding level of agreement between the experimental data and the proposed model. The RSM results revealed maximum CMP and YCH4 values of 409.82 ml and 178.95 ml/g VS respectively, obtained for optimum load values of 2.17 g VS/L and HRT of 15 h. The results emphasize the environmental and economic significance of AD, providing a sustainable waste management solution that helps reduce greenhouse gas emissions and organic pollution. Additionally, it generates valuable biogas and biofertilizers, presenting economic opportunities through renewable energy production and resource recovery. This approach not only alleviates the environmental burden of vinasse but also enhances the economic viability of ethanol production by creating additional revenue streams.

The effect of olive pomace hydrochar (OPHC) on food waste (FW) anaerobic digestion (AD) was investigated experimentally at five concentrations (5.85, 10, 20, 30, and 34.11 g/L). The selective concentrations are based on an experimental approach that was utilized to study the effect of adding 10-30 g/L OPHC to the AD of FW. The highest experimental methane yield (YCH4) and biodegradability are obtained for 10 and 20 g/L of OPHC, with 33 and 82 % improvement, respectively. Response surface methodology (RSM) was used to assess the impact of independent factors, including hydraulic retention time (HRT) and olive pomace hydrochar (OPHC) added, on YCH4. The R2 of 0.9073 and 0.9485 are obtained for YCH4 using face-centered and circumscribed designs, respectively, due to the model's accuracy. The optimal YCH4 was 428.81 ml/g VS with an OPHC added of 20 g/L and an HRT of 20 days.

Coffee is present in every street in the world and is without a doubt one of the most consumed beverages. Moreover, it is the third most consumed drink in the world. Recent estimations from the International Coffee Organization put. The world coffee production at about 6 million tons per year. Its uncontrolled disposal can cause environmental problems, but if handled properly, it can be processed into pellets, and used as an energy source. In the present study, the production of energy from coffee waste (CW) is an interesting alternative to traditional production lines. The objective of this study is to calculate the energetic potential (Ep), which can be generated by anaerobic digestion (AD) and thermochemical conversion (TC), of the organic fraction of CW in the city of Kenitra, Morocco. An elementary analysis allows us to estimate the calorific value by the TC. The lower and higher calorific values were estimated to be: 18.71 and 20.28 MJ/Kg, respectively. Ep results by AD and CT were 0.25 and 1.3 MWh/t, respectively.

The anaerobic digestion (AD) study for the valorization of poultry slaughterhouse waste (PSHW) was assessed at laboratory scale and in mesophilic conditions. Different loads, given gradually from 0.5 g VS/L to 3 g VS/L, were used to evaluate the methane production from PSHW via AD. The highest cumulative methane production (CMP) and methane yield (YCH4) were observed for the 2 g VS/L and 1 g VS/L added loads, with values of 566 Nml and 378 Nml/g VS, respectively, in a HRT of 140 h. The efficiency of the process was examined using a response surface method-central composite design (RSM-CCD) to examine the impact of independent variables such as load and HRT on CMP and YCH4. A statistical analysis of variance (ANOVA) was carried out to evaluate the suitability of the developed model. The YCH4 results showed a probability value (P-value)

Anaerobic digestion of the date palm empty fruit bunch is a promising technology for both solid waste management and biogas production. The date palm empty fruit bunch is a lignocellulosic waste that takes more time for degradation and has a low biodegradability, thus pretreatment is needed to improve anaerobic biodegradation. In this study, the substrate was pretreated with different ratios of alkali-NaOH: 6, 18 and 30% (w/w) (ratio weight of NaOH / weight of Volatile Solid) for 10 min at room temperature to evaluate the effect of high alkali concentration on the methane potential and biodegradability. The experiment was conducted in a 5 L batch reactor under mesophilic conditions (37°C). The methane potential of the untreated substrate was 98.5 NmL/gVS. The best methane potential improvement of 104% was achieved in the treatment of 18% (w/w) (204 NmL/gVS) with a biodegradability of 50%. Besides, two kinetic models were used to fit the experimental methane potentials and to explore process parameters (Modified Gompertz and Transference function). The best fit for predicting the parameters of methane production was observed for the 18% (w/w) pretreatment using the transference function, with a maximum methane production rate of 5 NmL/gVS.d.

Methanization is a technology that involves complex biological reactions and it is the subject of several scientific studies. The paper aims to evaluate the effect of the combined mechanical and ultrasonic pretreatment (CMUP) on the anaerobic digestion (AD) of the household organic waste fraction in Morocco (HOWF), using a continuous stirred tank reactor (CSTR) at mesophilic conditions.This article presents and compares a results obtained by operating two experiments in lab scale reactors with mechanical pretreatment (MP) and with CMUP. The experiment with MP was considered in this study as a control. During the handling period, the effect of CMUP on the AD of HOWF was studied. The process was evaluated in terms of methane production and biodegradability. The stability was maintained within correct parameters throughout the process for each experiment, while the methane yield and biodegradability of the control and CMUP experiments were 382 (mL CH4 g−1VS) (0°C, 1 atm), 72%, and 493 (mL CH4 g−1VS) (0°C, 1 atm), 86 % respectively. This shows clearly that the CMUP enhance the methane production and increase the biodegradability, suggesting that this combination pretreatment improve the hydrolysis and methanogenesis phases of the process.A kinetic study on anaerobic digestion results using the first order model was also used. The mathematical model shows a good fit with the experimental data. Keywords: Anaerobic digestion, HOWF, Mechanical pretreatment, Ultrasonic pretreatment, Methane yield, Biodegradability

Solar biogas system production offers the possibility to simultaneously produce heat, electricity and to treat waste products as well as to reduce greenhouse gas emissions in the industrial sector. In this paper, we report on the development of an experimental solar biogas prototype to valorize the biomass generated by the Moroccan paper industry in order to reduce its carbon footprint. This paper presents an integrated solution to an environmental and energy problem of the companies that generate wet waste biomass. The current new prototype consists of a biogas production system using liquid biomass, a solar installation, and thermodynamic storage derived from a heat pump. Energy balances carried out show that the solar system can reach a thermal efficiency of 70%; the thermal losses of the system are around 53% for the biogas system and 22.6% for the storage and piping system. Further, the results found indicate the average heat demand of the digester reactor is 302 kWh per month, the solar system produced 284 kWh per month (94%) in worth case, which means the solar system is the main source energy and the system solar biogas is a self-energy system. Besides, it was found that the pilot solar biogas system produces about 1100 L of biogas, the analysis of biogas produced prove that it contains 74% of CH4 (814 L) and processes about 3000 L of industrial biomass daily, the biogas conversion efficiency of the whole system is 42%. The economic potential of the current solar biogas system in terms of electricity savings reached 2 MWh per month. The life cycle savings of the current solar system instead of purchasing electricity to meet the energy needs of the biogas process is approximately $4687. Annual emissions of (CO2), carbon monoxide (CO), and nitrogen oxides (NOx) are reduced by 69%, 71%, and 70% respectively. Upscaling the current prototype system to 700 m3 (reactor volume) for the case study of cardboard company industry, shows that the yearly bio-methane (CH4) production is around 52,836 m3 per year, which represent 64% of the total fuel consumption for the current case of cardboard recycling and packaging company.

The anaerobic digestion (AD) has become an alternative source and an attractive treatment method. Up-flow Anaerobic Sludge Blanket (UASB) digester has been designed to treat the Recycled paper mill wastewater (RPMW) in Morocco. This paper provides a research on anaerobic digestion of RPMW using UASB technology. The UASB digester was designed following the characterization of wastewater and the feed rate, with the volume of 70 liters. The UASB reactor treating the RPMW was operated for 130 days with minimal overload problems. The experiments were carried out in the mesophilic temperature (37 °C) at different organic loading rates (OLR). A daily analysis was performed to ensure the efficiency of the digester. In this study, the AD experiment was performed in continuous mode with an effluent inlet flow rate equal to 1 L/h. Using the optimal OLR value 5.18 g COD/Ld and with an effluent 5,7 g COD/L, a biogas yield of 92 N mL/g COD removed (at normal temperature and pressure) was obtained during the RPMW anaerobic treatment. The reactor was operated at an optimal hydraulic retention time (HRT) of 15.14 h with a biogas production volume of the optimal value 62.5 L/d. These results indicate that RPMW can be effectively treated in a UASB reactor with the advantage of producing biogas. We tested our system with RPMW, to see the production capacity of the UASB system, which the objective is to develop the system for the industrial scale. Keywords: Anaerobic digestion, Biogas, HRT, OLR, Up flow - anaerobic sludge blanket, Reactor and RPMW