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The conventional application of a pulp and paper mill, in which black liquor is typically concentrated and burnt, is compared with the upgrading gasification route for methanol (MeOH) and dimethyl ether (DME) co-production. This comparison is made in terms of exergy efficiency and environmental impact indicators, under different utilities supply scenarios. The combined energy integration and exergy analysis is used to identify the potential improvements related to the decarbonization and mitigation of the process irreversibility. The exergy efficiencies of the conventional scenario and the integrated plants average 40% and 45%, respectively, while the overall emission balances vary from 1.97 to -0.07 tCO2/tPulp, respectively. These results reinforce the relevance of the electricity import from the Brazilian mix for pushing upwards the share of renewable energy resources in the production of traditionally fossil-based chemicals and fuels, which could be an important decision variable in favor to the exploration of forest-based integrated biorefineries.

The black liquor is a byproduct of the kraft pulping process that contains more than half of the exergy content in the total woody biomass fed to the digester, representing a key supply of renewable energy to the pulping process. In this work, the conventional scenario of the black liquor use (i.e., concentration and combustion) is compared with the black liquor upgrading (via) gasification process for ammonia production in terms of economics, exergy efficiency and environmental impact. The combined energy integration and exergy analysis is used to identify the potential improvements that may remain hidden to the energy analysis alone, namely, the determination and mitigation of the process irreversibility. As a result, the exergy efficiencies of the conventional and the integrated cases average 40% and 42%, respectively, whereas the overall emission balance varies from 1.97 to −0.69 tCO2/tPulp, respectively. The negative CO2 emissions indicate the environmental benefits of the proposed integrated process compared to the conventional kraft pulp mill.

RESUMO A Carbonização hidrotermal (HTC) de cascas do fruto de Magonia pubescens A. St. Hil. Sapindaceae (Tingui do cerrado) é apresentada como uma proposta inédita na produção de hydrochars a partir de precursores de espécies do Cerrado Brasileiro, onde se verificou a influência da temperatura nas propriedades dos materiais obtidos. Os hyrochar obtidos foram caracterizados em termos de rendimento em peso, análise elementar e estimativa do poder calorífico superior (PCS), análise de espectroscopia na região do infravermelho (FT-IR), difratometria de raios-x (DRX) e avaliação da capacidade de adsorção. O aumento da temperatura afetou negativamente o rendimento do hydrochar, o qual variou entre 46,25 % e 27,42%, nas temperaturas de 170 e 190 °C, respectivamente. Hydrochars com maior teor de carbono (64,10%) foram obtidos em baixa temperatura (170 °C), o qual também apresentou maior poder calorífico superior (23,94 MJ kg-1) e área superficial específica (44,0 m2.g-1). A evolução das razões atômicas H/C e O/C indicou processos de desidratação e descarboxilação durante a carbonização hidrotérmica. As isotermas de adsorção-dessorção de N2 a -176 ºC, resultantes da análise das propriedades texturais e estruturais, demonstraram a presença de mesoporos na estrutura dos hydrochars. Na avaliação da capacidade de adsorção com azul de metileno, a isoterma de Langmuir foi a que melhor explicou o comportamento de adsorção, tendo os hydrochars obtidos a 170 e 180 °C as maiores capacidades de adsorção (139,38 e 202,40 mg g-1, respectivamente). Os resultados indicaram a carbonização hidrotermal de cascas do fruto de tingui como uma nova estratégia para o desenvolvimento de hydrochars com alto rendimento, teor de carbono elevado e alta eficiência de adsorção, valores superiores a diversos trabalhos encontrados na literatura. ABSTRACT The hydrothermal carbonization (HTC) of bark of the fruit of Magonia pubescens A. St. Hil. Sapindaceae (Tingui do Cerrado) presents as an unprecedented proposal for the production of hydrochars from precursors of Brazilian Cerrado species, where the influence of temperature on the properties of the obtained materials is verified. The obtained hydrochar were characterized in terms of yield, elemental analysis, estimation of the higher calorific value, infrared spectroscopy, X-ray diffractometry, and methylene blue adsorption. The temperature increases affected negatively hydrochar yield, which varied between 46,25% and 27,42%, at temperatures of 170 and 190 °C, respectively. Hydrochar with higher carbon content (64,10%), higher calorific value (23,94 MJ kg-1) and specific surface area (44,0 m2 g-1) were obtained at 170 °C. The evolution of the atomic ratios H/C and O/C indicated processes of dehydration and decarboxylation during hydrothermal carbonization. The adsorption-desorption isotherms of N2 at -176º C resulting from the analysis of the textural and structural properties demonstrated the presence of mesopores in the structure of the hydrochars. In the evaluation of the adsorption capacity with methylene blue, the adsorption data correlated well with the Langmuir isotherm. In this analysis, the hydrochars obtained at 170 and 180 °C demonstrated the highest adsorption capacity (Qmax = 139,38 and 202,40 mg g-1, respectively). The results indicated the hydrothermal carbonization of the bark of the tingui fruit as a new strategy for the development of hydrochars with high yield, high carbon content and high adsorption efficiency, higher values than several papers found in the literature.

O corrente projeto refere-se a um processo de avaliação sob o qual foram submetidas as cinco maiores hortas do município de Inhumas. O objetivo dessa pesquisa é identificar se há alguma horta orgânica em tal município e, ao final da pesquisa, orientar os proprietários das hortas convencionais, seja por distribuição de material, oficinas ou palestras, a investirem na mudança para hortas orgânicas de forma gradual. Um outro objetivo da pesquisa é disseminar a ideia do uso do lixo orgânico da cidade de Inhumas para geração dos adubos e fertilizantes orgânicos. Dessa forma, seria alcançada a meta de se obter um negócio sustentável que também cooperaria para melhor controle do lixo na cidade.

O projeto atual refere-se à análise do problema do lixo eletrônico no Brasil. Tal análise objetiva caracterizar a amplitude do problema e descobrir soluções já implementadas em outros países e, até mesmo, em outros estados brasileiros. A intenção é de que tal pesquisa nos dê suporte para a composição de um projeto de empresa incubadora no IFG, campus Inhumas, que tenha como atividades a coleta e reparo de equipamentos descartados pela sociedade. Além da importância de se ter uma incubadora do campus, tem sido visada também a execução de um projeto que contribua com o meio ambiente e trabalhe a conscientização da sociedade.

The conventional configuration of a pulp mill, in which black liquor is concentrated and burnt, is compared to the upgrading gasification routes for methanol (MeOH) or dimethyl ether (DME) co-production. To this end, various exergy-based and environmental impact indicators are assessed in the light of different utility supply scenarios. The combined exergy and energy integration analysis are used to identify potential improvements related to the decarbonization and mitigation of the process irreversibility. As a result, the exergy efficiencies of the conventional scenario and the integrated plants average 40% and 45%, respectively, whereas the overall CO 2 emission balances vary from 1.97 to -0.07 t CO2 /t Pulp , respectively. Additionally, an incremental economic analysis that envisages future carbon taxation scenarios suggests that only MeOH or DME co-production routes with partial electricity import may economically outperform the conventional kraft pulp mill for moderate carbon taxations. These results highlight the relevance of the electricity import from the Brazilian mix for pushing upwards the share of renewable energy resources in the production of traditionally fossil-based fuels and chemicals. (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

In this work, the gasification of the black liquor is proposed as an alternative ammonia production route. Due to the seasonal variation of the energy prices, a multi-time integration approach that combines different technologies and energy inputs is used to identify the most suitable operating conditions and arrangements that minimize the energy resources consumption. As a result, the integration of technologies such as power-to-gas systems, carbon capture and injection units, along with liquid fuel storage, may help offsetting the intermittency of the renewable energy resources and increasing the economic revenues of the integrated pulp and ammonia plant. The optimal CO2 management and synthetic natural gas storage may ensure a reliable operation even during the strained periods of the electricity grid. Also, the credits obtained from the injection of biogenic CO2 emissions may compensate for the investment cost associated to the implementation of these new technologies.