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Energy-Efficient Routes for the Production of Gasolinefrom Biogas and Pyrolysis Oil — Process Design and Life-CycleAssessment

View Article: PubMed Central - PubMed

ABSTRACT

Twonovel routes for the production of gasoline from pyrolysisoil (from timber pine) and biogas (from ley grass) are simulated,followed by a cradle-to-gate life-cycle assessment of the two productionroutes. The main aim of this work is to conduct a holistic evaluationof the proposed routes and benchmark them against the conventionalroute of producing gasoline from natural gas. A previously commercializedmethod of synthesizing gasoline involves conversion of natural gasto syngas, which is further converted to methanol, and then as a laststep, the methanol is converted to gasoline. In the new proposed routes,the syngas production step is different; syngas is produced from amixture of pyrolysis oil and biogas in the following two ways: (i)autothermal reforming of pyrolysis oil and biogas, in which thereare two reactions in one reactor (ATR) and (ii) steam reforming ofpyrolysis oil and catalytic partial oxidation of biogas, in whichthere are separated but thermally coupled reactions and reactors (CR).The other two steps to produce methanol from syngas, and gasolinefrom methanol, remain the same. The purpose of this simulation isto have an ex-ante comparison of the performance of the new routesagainst a reference, in terms of energy and sustainability. Thus,at this stage of simulations, nonrigorous, equilibrium-based modelshave been used for reactors, which will give the best case conversionsfor each step. For the conventional production route, conversion andyield data available in the literature have been used, wherever available.Theresults of the process design showed that the second method (separate,but thermally coupled reforming) has a carbon efficiency of 0.53,compared to the conventional route (0.48), as well as the first route(0.40). The life-cycle assessment results revealed that the newlyproposed processes have a clear advantage over the conventional processin some categories, particularly the global warming potential andprimary energy demand; but there are also some in which the conventionalroute fares better, such as the human toxicity potential and the categoriesrelated to land-use change such as biotic production potential andthe groundwater resistance indicator. The results confirmed that eventhough using biomass such as timber pine as raw material does resultin reduced greenhouse gas emissions, the activities associated withbiomass, such as cultivation and harvesting, contribute to the environmentalfootprint, particularly the land use change categories. This givesan impetus to investigate the potential of agricultural, forest, oreven food waste, which would be likely to have a substantially lowerimpact on the environment. Moreover, it could be seen that the sourceof electricity used in the process has a major impact on the environmentalperformance.

No MeSH data available.


Related in: MedlinePlus

A comparison of human toxicity potential(HTP) for the three cases.
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fig9: A comparison of human toxicity potential(HTP) for the three cases.

Mentions: On the other hand, the results of the human toxicity potential(refer to Figure 9),show that the Base case has a more favorable profile. The HTP reflectsthe effect of certain substances that can affect human health. Thechief contributors in the new processes (apart from the electricityconsumption, which is once again comparable) are the biomass-relatedinputs, that is, the cultivation and harvesting of timber pine, andthe energy for harvesting ley grass for biogas production. As mentionedearlier, these steps involve use of electric power from the grid,as well as consumption of diesel. Thus, these steps contribute measurablyto the HTP. Also, the oxygen consumption has an impact on the HTP,again because it consumes fossil-fuel based energy. Since the amountof oxygen required in the Base case is more, it has a higher contributionfrom this unit than the ATR and CR cases. Next, we look at land usechange impacts for the three cases.


Energy-Efficient Routes for the Production of Gasolinefrom Biogas and Pyrolysis Oil — Process Design and Life-CycleAssessment
A comparison of human toxicity potential(HTP) for the three cases.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384482&req=5

fig9: A comparison of human toxicity potential(HTP) for the three cases.
Mentions: On the other hand, the results of the human toxicity potential(refer to Figure 9),show that the Base case has a more favorable profile. The HTP reflectsthe effect of certain substances that can affect human health. Thechief contributors in the new processes (apart from the electricityconsumption, which is once again comparable) are the biomass-relatedinputs, that is, the cultivation and harvesting of timber pine, andthe energy for harvesting ley grass for biogas production. As mentionedearlier, these steps involve use of electric power from the grid,as well as consumption of diesel. Thus, these steps contribute measurablyto the HTP. Also, the oxygen consumption has an impact on the HTP,again because it consumes fossil-fuel based energy. Since the amountof oxygen required in the Base case is more, it has a higher contributionfrom this unit than the ATR and CR cases. Next, we look at land usechange impacts for the three cases.

View Article: PubMed Central - PubMed

ABSTRACT

Twonovel routes for the production of gasoline from pyrolysisoil (from timber pine) and biogas (from ley grass) are simulated,followed by a cradle-to-gate life-cycle assessment of the two productionroutes. The main aim of this work is to conduct a holistic evaluationof the proposed routes and benchmark them against the conventionalroute of producing gasoline from natural gas. A previously commercializedmethod of synthesizing gasoline involves conversion of natural gasto syngas, which is further converted to methanol, and then as a laststep, the methanol is converted to gasoline. In the new proposed routes,the syngas production step is different; syngas is produced from amixture of pyrolysis oil and biogas in the following two ways: (i)autothermal reforming of pyrolysis oil and biogas, in which thereare two reactions in one reactor (ATR) and (ii) steam reforming ofpyrolysis oil and catalytic partial oxidation of biogas, in whichthere are separated but thermally coupled reactions and reactors (CR).The other two steps to produce methanol from syngas, and gasolinefrom methanol, remain the same. The purpose of this simulation isto have an ex-ante comparison of the performance of the new routesagainst a reference, in terms of energy and sustainability. Thus,at this stage of simulations, nonrigorous, equilibrium-based modelshave been used for reactors, which will give the best case conversionsfor each step. For the conventional production route, conversion andyield data available in the literature have been used, wherever available.Theresults of the process design showed that the second method (separate,but thermally coupled reforming) has a carbon efficiency of 0.53,compared to the conventional route (0.48), as well as the first route(0.40). The life-cycle assessment results revealed that the newlyproposed processes have a clear advantage over the conventional processin some categories, particularly the global warming potential andprimary energy demand; but there are also some in which the conventionalroute fares better, such as the human toxicity potential and the categoriesrelated to land-use change such as biotic production potential andthe groundwater resistance indicator. The results confirmed that eventhough using biomass such as timber pine as raw material does resultin reduced greenhouse gas emissions, the activities associated withbiomass, such as cultivation and harvesting, contribute to the environmentalfootprint, particularly the land use change categories. This givesan impetus to investigate the potential of agricultural, forest, oreven food waste, which would be likely to have a substantially lowerimpact on the environment. Moreover, it could be seen that the sourceof electricity used in the process has a major impact on the environmentalperformance.

No MeSH data available.


Related in: MedlinePlus