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In this study, by taking the compression separation process of a biogas project as a research subject, a multistage compression process was simulated using Aspen Plus software. The exergy analysis of the biogas project under multistage compression and adiabatic or isothermal conditions was performed employing the thermodynamic principle. The results showed that the biogas exergy increased with pressure during the compression process and correspondently decreased in the interstage cooling process. Further, the compression series increased with the increase in efficiency, but the increase was gradual. The results of the example study of the four-stage compression process are as follows: the process exergy increased by ~83.07 kW, the process exergy efficiency was ~75.56%, and the recovery exergy potential was ~12.6 kW. In this study, the allocation of compression ratios and the selection of compression stages within the multistage compression process were analyzed by Aspen Plus was used to analyze., This analysis can ultimately help others design efficient multistage compression systems that reduce energy losses.

To achieve the goal of developing high-performance lubricant additives for industrial lubrication. Herein, tetradecylphosphonic acid (TDPA) modified Ti3C2TX and graphene oxide (GO) were used as nanohybrid lubricant additives in the polyalphaolefins base oil (PAO6). The high-speed reciprocating friction and wear test shows that TDPA–Ti3C2/GO is an efficient friction-reduction and antiwear additive. The base oil mixed with 0.05 wt%TDPA–Ti3C2/0.05 wt% GO exhibits the lowest coefficient of friction (COF) and wear rate with the value of 0.09 and 4.4 × 10–6 mm3/Nm, decreased by 54.5 and 90.0% compared with pure PAO6 oil, respectively. Detailed characterization analysis shows that the tribological film of the modified TDPA–Ti3C2/GO nanohybrids oil-lubricated surface was mainly composed of PAO6, TDPA, GO, and iron oxide. This indicates that the friction-reduction and antiwear mechanism of TDPA–Ti3C2/GO in base oil lies in the adsorption of the two nanomaterials and the formation of a self-lubricating film on the rubbing interface. This study provides a new approach to the design of nanohybrid lubricant additives and creates new prospects for the application of nanomaterials in tribology. [ABSTRACT FROM AUTHOR]

Laser‐assisted current injection treatment, also known as laser‐enhanced contact optimization (LECO), has great potential to reduce front contact resistance and metal‐induced recombination of n‐type tunnel oxide‐passivated contact (n‐TOPCon) solar cells, thereby improving the cell efficiency. Herein, the interfacial Ag–Si contact characteristics on boron‐doped p+ emitters and the electrical properties of industrial n‐TOPCon solar cells that feature a LECO treatment and a specific Ag paste are investigated and compared with those of n‐TOPCon solar cells with a standard Ag/Al paste process. LECO causes some current‐fired contacts that, when removed by sequential selective etching, leave bowl‐shaped imprints on the emitter, indicating that isotropic alloying behavior occurs between Ag and Si at these local positions during LECO. Unlike the standard Ag/Al metallization process, the LECO process does not significantly damage the passivation layer or emitter. More interestingly, the n‐TOPCon solar cells prepared with the specific Ag paste do not initially form an effective metal–semiconductor contact, with an average efficiency of only 0.14%, which increases to 25.65% after LECO treatment, even 0.2%abs higher than that of the reference counterparts with standard Ag/Al electrodes. Ultimately, a physical model of LECO‐induced Ag–Si contact formation on boron emitters is proposed. [ABSTRACT FROM AUTHOR]