\nIn class we discussed stoichiometric (ideal) combustion of hydrocarbons in ideal dry air, and introduced the equivalence ratio F. Consider the combustion of hydrocarbon CxHy, where x and y are known for a given hydrocarbon (e.g., for methane, CH4, x = 1, y = 4). The general equation for non-ideal combustion of hydrocarbon CxHy is CxHy +a(O2+3.76N2) = bCO2+cH2O+dN2 +eCO+fO2 +trace where molar coefficients a, b, c, d, e, and f need to be calculated to balance the equation, and “trace” means small quantities of other pollutants, such as alcohols, NOx, aldehydes, etc.<\/p>\n
(a) Generate algebraic expressions for coefficients a, b, c, d, e, and f as functions of each other and of (known) x and y as far as possible. In particular, provide equations for b, c, d, and f as functions of x, y, a, and e. Hint: You will not be able to solve explicitly for all the coefficients, since there are 6 unknowns and only 4 elements in the equation with which to generate expressions (C, H, O, and N).<\/p>\n
(b) Consider the stoichiometric case in which there is no excess air, a = astoich, and there is no CO or excess air on the RHS (e = f = 0). Generate expressions for coefficients a (a = astoich), b, c, and d as functions of only x and y.<\/p>\n
(c) Gasoline is mostly octane, C8H18. For octane, calculate the molar coefficients and write the final chemical equation for the stoichiometric case.<\/p>\n
(d) Now consider combustion of octane with F = 0.833333… Also, molar coefficient e is known to be 2 in this particular case. Calculate the molar coefficients and write the final chemical equation for this case. Is this rich or lean combustion?<\/p>\n
(e) Calculate the mol fraction of CO (in PPM) of the exhaust gas products of the case of Part (d).<\/p>\n","protected":false},"excerpt":{"rendered":"
In class we discussed stoichiometric (ideal) combustion of hydrocarbons in ideal dry air, and introduced the equivalence ratio F. Consider the combustion of hydrocarbon CxHy, where x and y are known for a given hydrocarbon (e.g., for methane, CH4, x Read More …<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-6890","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/posts\/6890","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/comments?post=6890"}],"version-history":[{"count":0,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/posts\/6890\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/media?parent=6890"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/categories?post=6890"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/tags?post=6890"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}