Catalytic Supercritical Water Gasification: Continuous Methanization of Chlorella vulgaris

Abstract

Continuous catalytic supercritical water gasification (CSCWG; 400 °C, 28 MPa) of microalgal biomass (Chlorella vulgaris) was carried out at the microalgae production site of ZHAW in Wädenswil (Switzerland) nonstop over a period of 100 h. Microalgae slurries (3–15 wt %) were successfully gasified to a methane-rich gas for 55 h. The low total organic carbon of the reactor effluent (<400 mg L–1) recorded during that period demonstrated the high catalytic activity of the Ru/C catalyst for converting microalgae to the gaseous products. The addition of a sulfur removal step with a commercial zinc oxide adsorbent was essential for protecting the catalyst against sulfur poisoning. A brine effluent rich in nutrients (N, K, S, P, Na) was withdrawn continuously from a salt separator. In summary, the use of a zinc oxide adsorbent upstream of the catalyst bed, together with a higher ruthenium loading of the catalyst, improved the long-term performance of the CSCWG process significantly.

Recent Advances in Carbon Dioxide Conversion: A Circular Bioeconomy Perspective

“…Supercritical water gasification (SCWG) enables oxidization of wet microalgal biomass in a short reaction time, in which the proper catalyst is crucial for high gas conversion and selectivity toward combustible gases [162]. A continuous SCWG of Chlorella vulgaris has been demonstrated in Switzerland to produce methane-rich gas (55~60%) [163].…”

Avaliação do poder calorífico da biomassa algal obtida por coagulação-floculação

“…Além disso, o cultivo ainda permite a incorporação de CO 2 gerado em processos industriais, adicionando-se um benefício extra (JANKOWSKA et al, 2017). Por tudo isso, as microalgas têm se consolidado como matriz essencial para os biocombustíveis de terceira geração, abrindo uma nova dimensão na indústria de energia renovável (PENG et al, 2017).…”

Cluster integrals and virial coefficients for realistic molecular models

“…However, the past decade has brought renewed attention, with considerable advances seen in theory, methods and applications [6][7][8][9][10][11][12]. While the approach remains inapplicable to condensed phases, there is an enormous range of non-trivial and technologically important behavior encompassed by the supercritical region to which it can apply [13][14][15][16][17][18][19][20][21]. Considering that first-principles calculations of ideal-gas properties now routinely outperform experiment in accuracy and cost [22][23][24][25][26], it should be self-evident that cluster integrals-which proceed naturally and methodically from the ideal-gas starting point-form the next natural frontier to advance ab initio computational chemistry.…”

“…engineering. Supercritical water (as studied here) is itself important to diverse areas such as geophysics [13] and gasification of biomass [14], while applications of supercritical fluids more generally encompass a broad range of science and technology, including separations [15], reaction engineering [16], nanotechnology [17], crystallization [18], power generation [19], carbon capture [20], and more [21]. These fields could more rapidly advance with access to predictive (ideally first-principles) methods for computing properties of arbitrary compounds and their mixtures.…”