Chloro- and bromo-fluoro olefin compounds useful as organic rankine cycle working fluids

A process for converting thermal energy to mechanical energy comprising:

• heating a working fluid with a low grade thermal energy heat source to a temperature sufficient to vaporize the working fluid and form a pressurized vapor of the working fluid;
• and
• causing the pressurized vapor of the working fluid to perform mechanical work;
• wherein the working fluid comprises at least one compound having the formula (I):
• wherein R1, R2, R3, and R4 are each independently selected from the group consisting of:
• H, F, Cl, Br, and C1-C6 alkyl, at least C6 aryl, at least C3 cycloalkyl, and C6-C15 alkylaryl optionally substituted with at least one F, Cl, or Br, wherein formula (I) contains at least one F and at least one Cl or Br, provided that if formula (I) contains Br, then it also contains no hydrogen and wherein at least one of R1, R2, R3, and R4 is methyl, ethyl, or propyl, optionally substituted with at least one F, Cl, or Br.

A process for a binary power cycle comprising a primary power cycle and a secondary power cycle, wherein a primary working fluid comprising high temperature water vapor or an organic working fluid vapor is used in the primary power cycle, and a secondary working fluid is used in the secondary power cycle to convert thermal energy to mechanical energy wherein the secondary power cycle comprises:

• heating the secondary working fluid using a low grade thermal energy source to form a pressurized vapor and
• causing the pressurized vapor of the secondary working fluid to perform mechanical work,
• wherein the secondary working fluid comprises at least one compound having the formula (I):
• wherein R1, R2, R3, and R4 are each independently selected from the group consisting of:
• H, F, Cl, Br, and C1-C6 alkyl, at least C6 aryl, at least C3 cycloalkyl, and C6-C15 alkylaryl optionally substituted with at least one F, Cl, or Br, wherein formula (I) contains at least one F and at least one Cl or Br, provided that if formula (I) contains Br, then it also contains no hydrogen and wherein at least one of R1, R2, R3, and R4 is methyl, ethyl, or propyl, optionally substituted with at least one F, Cl, or Br.

A process for converting thermal energy to mechanical energy comprising a Rankine cycle system and a secondary loop;

• wherein the secondary loop comprises a thermally stable sensible heat transfer fluid interposed between a low grade thermal energy heat source and the Rankine cycle system and in fluid communication with the Rankine cycle system and the low grade thermal energy heat source to transfer heat from the heat source to the Rankine cycle system without subjecting a working fluid of the organic Rankine cycle system to heat source temperatures;
• wherein the Rankine cycle system working fluid comprises at least one compound having the formula (I):
• wherein R1, R2, R3, and R4 are each independently selected from the group consisting of:
• H, F, Cl, Br, and C1-C6 alkyl, at least C6 aryl, at least C3 cycloalkyl, and C6-C15 alkylaryl optionally substituted with at least one F, Cl, or Br, wherein formula (I) contains at least one F and at least one Cl or Br, provided that if formula (I) contains Br, then it also contains no hydrogen and wherein at least one of R1, R2, R3, and R4 is methyl, ethyl, or propyl, optionally substituted with at least one F, Cl, or Br.